CONTRACT OR GRANT Stanley Fay, Stephen Gates, Timothy Henderson, Lester Sackett, 205 p (Contract NAS9-17560) Sep. 1988 PUBLICATION DATE (NASA-CR-172095; R-2088; NAS 1.26:172095) Avail: NTIS HC The second Control Of Flexible Structures Flight Experiment AVAILABILITY SOURCE ADMINISTRATION VOLUME 27 NUMBER 23 / DECEMBER 8, 1989 Scientific and Technical Aerospace Reports A Semimonthly Publication of the National Aeronautics and Space Administration The activities of the FRG aerospace research organization DFVLR for 1987 are reported. In the research field of aeronautics, investigations were performed on Compas (a planning and decision aid for air traffic controllers) and on a delta wing (a contribution to the International Vortex Flow Experiment). Space-related activities were the German Front Experiment 1987 (an example for the mesoscale probing of the atmosphere) and wind tunnel testing of reentry bodies in the hypersonic range. In the field of energy technology, renewable energy sources for BadenWuerttemberg were investigated. Photographs, drawings, and diagrams are provided, and an English summary is given for each section. ESA 02 AERODYNAMICS Includes aerodynamics of bodies, combinations, wings, rotors, and control surfaces; and internal flow in ducts and turbomachinery. For related information see also 34 Fluid Mechanics and Heat Transfer. N89-28486* National Aeronautics and Space Administration. Langley Research Center, Hampton, VA. LOW-SPEED STATIC AND DYNAMIC FORCE TESTS OF A GENERIC SUPERSONIC CRUISE FIGHTER CONFIGURATION David E. Hahne Washington Oct. 1989 35 p (NASA-TM-4138; L-16599; NAS 1.15:4138) Avail: NTIS HC A03/MF A01 CSCL 01A Static and dynamic force tests of a generic fighter configuration designed for sustained supersonic flight were conducted in the Langley 30- by 60-foot tunnel. The baseline configuration had a 65 deg arrow wing, twin wing mounted vertical tails and a canard. Results showed that control was available up to C sub L,max (maximum lift coefficient) from aerodynamic controls about all axes but control in the pitch and yaw axes decreased rapidly in the post-stall angle-of-attack region. The baseline configuration showed stable lateral-directional characteristics at low angles of attack but directional stability occurred near alpha wing shielded the vertical tails. The configuration showed positive 25 deg as the effective dihedral throughout the test angle-of-attack range. Forced oscillation tests indicated that the baseline configuration had stable damping characteristics about the lateral-directional axes. Author = N89-28487# Midwest Research Inst., Golden, CO. Solar Energy THREE-DIMENSIONAL AIRFOIL PERFORMANCE (Contract DE-AC02-83CH-10093) (DE89-009443; SERI/TP-217-3505; CONF-890717-2) Avail: NTIS HC A02/MF A01 The objective of this comprehensive research program was to study the effects of Horizontal Axis Wind Turbine (HAWT) blade rotation on aerodynamic behavior below, near, and beyond stall. The flow angle sensor used to measure Angle Of Attack (AOA) is described along with how the sensor was calibrated, and results are given of pressure integrations on the blade. Aerodynamic, load, flow visualization, and inflow measurements were made on a 10-m, three-bladed, downwind HAWT. A video camera was mounted on the rotor to record video images of tufts attached to the low pressure side of a constant-chord, zero-twist blade. Load measurements were made using strain gages mounted every 10 percent of the blade's span. Pressure taps were located at 32 chordwise positions and revealed pressure distributions comparable with wind tunnel data. Inflow was measured using a vertical plane array of eight propvane and five triaxial (U-V-W) prop-type anemometers located 10 m upwind in the predominant wind direction. Results show evidence of stall hysteresis and unsteadiness at high AOA. Correlations with analytical predictions and wind tunnel tests show good agreement at low AOA and poor agreement at high AOA. DOE N89-28488# General Dynamics Corp., Fort Worth, TX. Atlee M. Cunningham, Jr., Todd Bushlow, John R. Mercer, Tim A. Volume 1 presents the test program, correlations with other data, and discussions of the specific objectives of this investigation. In general it was shown that the small scale wind tunnel and water tunnel test techniques do provide reasonable dynamic force and moment data for a wide variety of planforms and conditions. The force testing of small-scale models in either a small wind tunnel or a water tunnel was investigated as an inexpensive and quick means to obtain meaningful dynamic force and moment data representative of rapidly maneuvering full-scale aircraft. Force tests of flat-plate semi-span models were conducted in the General Dynamics Aerodynamic Development Facility (ADF) which is a small 14x14 in. low speed wind tunnel. Oscillatory model motions up to 48 deg (peak to peak) amplitude were tested at frequencies of 1 to 3 Hz. Force tests of flat and three-dimensional full span models were conducted in the General Dynamics Hydroflow Facility (HFF) which is a horizontal flow water tunnel with a 24x24 in. test section. Pitch/pulse model motions were tested for conditions similar to those tested in the ADF. GRA L. D. MacLaren Feb. 1989 6 p The vortex flow patterns over thin delta wings were photographed during experiments in a vertical water tunnel making use of appropriate flow visualization techniques. The flow geometry for these wings was also calculated using the VORSBA vortex flow computer program. A comparison is made between the calculated and experimental results and discrepancies between them are discussed. GRA N89-28490# Air Force Inst. of Tech., Wright-Patterson AFB, OH. School of Engineering. GLIDER GROUND EFFECT INVESTIGATION M.S. Thesis (AD-A209152; AFIT/GAE/ENY/89J-2) Avail: NTIS HC This research used glider flight tests and optimized glider simulations to evaluate the aerodynamics of ground effect and to determine the optimum flight profile for maximum gliding range in gliders. A series of 122 sorties were flown in the Grob G-103 Twin II and the Let L-13 Blanik gliders on a specially designed very low altitude speed course. Radar tracking data were used to determine the glider position and velocity, and a 3 degree of freedom glider performance simulation was used to determine the glider parasite and induced drag coefficients in ground effect. Lifting line derived predictions of ground effect induced drag reduction developed by Dr. Sighard Hoerner were found to be accurate at altitudes above 20 percent wingspan but were up to 16 percent too optimistic at low altitudes. A revised prediction of ground effect induced drag reduction was developed based on the flight test data, and this revised prediction was used along with a turbulent boundary layer wind model in two optimization algorithms to develop the optimum flight profiles for maximum range gliding flight. GRA N89-28491# Air Force Geophysics Lab., Hanscom AFB, MA. THE FIRST LARGE BALLOON LAUNCH FROM ANTARCTICA Final Scientific Report John Ground, Kenneth Dallas, Ralph Cowie, and Willard F. Thorn 26 Sep. 1988 103 p (AD-A207735; AFGL-TR-88-0265; AFGL-ERP-1015) Avail: NTIS HC A06/MF A01 CSCL 01/3 This collection of five papers discusses the many practical problems, logistics, metrological planning, flight history and recovery operations for the first very large (11.6M cu ft) stratospheric balloon launched from Antarctica. The on-board Gamma Ray Advanced Detector (GRAD) was flown successfully to detect gamma ray emissions from Supernova 1987A. The 2500-lb payload was recovered from a 12,500-ft plateau by LC-130 aircraft. The instrumentation for command-control and telemetry, payload integration and testing, and the telemetry station installed aboard an LC-130 aircraft are described. An overview of the performance of the ARGOS satellite tracking and data-recovery system on this flight is included. GRA N89-28492# National Aerospace Lab., Tokyo (Japan). Structural SOME COMPUTATIONS OF UNSTEADY NAVIER-STOKES (NAL-TR-1004T; ISSN-0389-4010) Avail: NTIS HC A03/MF A01 Unsteady Navier-Stokes calculations around an airfoil/wing are demonstrated. 2D transonic flutter simulations are performed about the NACA 64A010 airfoil using not only a diagonal form of a Beam-Warming scheme but also a non-diagonal form. The effects of time accuracy of the algorithms on the flutter boundaries are checked by comparing two results. 3D unsteady computations around an oscillating wing in elastic motions are also carried out and the obtained results are compared with experimental data. It is found that the diagonal form of a Beam-Warming scheme is efficient in predicting the flutter boundaries of airfoils where the ANALYSIS OF LEADING EDGE SEPARATION USING A LOW ORDER PANEL METHOD Final Report Doral R. Sandlin Sep. 1989 26 p (Contract NCC2-226) (NASA-CR-185892; NAS 1.26:185892) Avail: NTIS HC A03/MF A01 An examination of the potential flow computer code VSAERO to model leading edge separation over a delta wing is examined. Recent improvements to the code suggest that it may be capable of predicting pressure coefficients on the body. Investigation showed that although that code does predict the vortex roll-up, the pressure coefficients have significant error. The program is currently unsatisfactory, but with some additional development it may become a useful tool for this application. Author N89-28494# Institut Franco-Allemand de Recherches, Saint-Louis (France). STUDY OF THE WING-VORTEX INTERACTION IN THREE 45 P 16 Aug. 1987 In FRENCH Original contains color illustrations (ISL-R-123/87; ETN-89-94856) Avail: NTIS HC A03/MF A01 The use of horseshoe vortices on the wing and of a turbulent network for the wake, permitted treatment in three dimensions of the case of a thin wing for steady flow and unsteady flow (incident wing with upstream vortex). For steady flow and large spans the calculated lift is close to the two dimensional value. For the unsteady case the variations in lift along the path of the vortex ESA are described. N89-28496# ESA National Aeronautical Lab., Bangalore (India). Computational and Theoretical Fluid Dynamics Div. ROLE OF SUPERCOMPUTER IN COMPUTATIONAL AERODYNAMICS N. R. Subramanian and Anand Kumar Jun. 1989 20 p (PD-CF-8925) Avail: NTIS HC A03/MF A01 An overview is given of the computational requirement for solving CFD problems. Also described are two examples, typical of two different types of approximation of Navier-Stokes equations, carried out on a Supercomputer. The first problem deals with the full potential transonic flow computations around a wing in a body fitted coordinate system, while the second deals with vortex flow computation on a low aspect ratio wing based on Euler equations using finite volume and Runge-Kutta time stepping approaches. Author |